You are viewing a plain text version of this content. The canonical link for it is here.
Posted to yarn-dev@hadoop.apache.org by "Andras Gyori (Jira)" <ji...@apache.org> on 2021/05/20 14:28:00 UTC
[jira] [Created] (YARN-10780) Optimise retrieval of configured node
labels in CS queues
Andras Gyori created YARN-10780:
-----------------------------------
Summary: Optimise retrieval of configured node labels in CS queues
Key: YARN-10780
URL: https://issues.apache.org/jira/browse/YARN-10780
Project: Hadoop YARN
Issue Type: Improvement
Reporter: Andras Gyori
Assignee: Andras Gyori
CapacitySchedulerConfiguration#getConfiguredNodeLabels scales poorly with respect to queue numbers (its O(n*m), where n is the number of queues and m is the number of properties set by each queue). During CS reinit, the node labels are often queried, however looking at the code:
{code:java}
for (Entry<String, String> stringStringEntry : this) {
e = stringStringEntry;
String key = e.getKey();
if (key.startsWith(getQueuePrefix(queuePath) + ACCESSIBLE_NODE_LABELS
+ DOT)) {
// Find <label-name> in
// <queue-path>.accessible-node-labels.<label-name>.property
int labelStartIdx =
key.indexOf(ACCESSIBLE_NODE_LABELS)
+ ACCESSIBLE_NODE_LABELS.length() + 1;
int labelEndIndx = key.indexOf('.', labelStartIdx);
String labelName = key.substring(labelStartIdx, labelEndIndx);
configuredNodeLabels.add(labelName);
}
}
{code}
This method iterates through ALL properties set in the configuration. For example in case of initialising 2500 queues, each having at least 2 properties:
2500 * 5000 ~= over 12 million iteration
There are some ways to resolve this issue while keeping backward compatibility:
# Create a property like the original accessible-node-labels, which contains predefined labels. If it is set, then getConfiguredNodeLabels get the value of this property, otherwise it falls back to the old logic. I think accessible-node-labels are not used for this purpose (though I have a feeling that it should have been).
# Collect node labels for all queues at the beginning of parseQueue and only iterate through the properties once. This will increase the space complexity in exchange of not requiring intervention from user's perspective.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-dev-unsubscribe@hadoop.apache.org
For additional commands, e-mail: yarn-dev-help@hadoop.apache.org